1. Field of the Invention
The invention relates primarily to pulleys and clutches and particularly to clutches having a pulley and a clutch housing assembly for use with a clutch rotor, although not wholly limited to such types of constructions. More particularly, the invention relates to a clutch housing and pulley assembly formed of stamped sheet metal components. Also, the invention relates to an improved method of installing a bearing in the pulley when forming the improved clutch housing and pulley assembly.
2. Description of the Prior Art
There are varieties of individual clutch and pulley constructions and combinations thereof of the type in which a clutch rotor is mounted on a drive shaft for drivingly engaging a clutch housing. The clutch housing is mounted on or is formed as an integral part of a pulley or similar driven member which is rotatably coupled with the clutch rotor upon the drive shaft reaching a predetermined speed. The clutch housing and pulley assembly is rotatably mounted on the drive shaft by bearings permitting the drive shaft to rotate freely with respect to the assembly without rotating the assembly until coupling engagement is achieved by the rotating clutch rotor.
There are numerous configurations and arrangements of the driven clutch housing and associated pulley assembly depending upon the particular application in which the clutch is intended for use. These assemblies are constructed in various sizes and of different materials. Many of these assemblies consist of a one-piece cast metal pulley and housing member, such as shown in Pat. No. 2,552,747. These cast metal members are susceptible to breakage due to flaws which may occur in the member during casting, and generally are heavier than similar size sheet metal members and to not provide good heat dissipation. Other constructions consist of a clutch housing and pulley assembly formed by stamping or metal spinning procedures, or combinations thereof. These stamped and spun pulleys are satisfactory for many applications but may require special reinforcements and modifications when used in clutch assemblies where relatively large torques and forces may be exerted on the pulley and clutch housing. These reinforcing components and modifications increase both the material and manufacturing costs of the clutch housing and pulley assembly.
It is more economical when manufacturing large quantities of most products such as clutches, to be able to use the same type and size of metal for as many of the components as possible. This enables greater quantites of the material to be purchased, usually at a reduced cost, resulting in fewer types of metal stock, thereby reducing inventory and storage requirements.
Another problem that is encountered with prior clutch constructions in which the pulley and clutch housing are formed as an integral member, whether formed of cast metal or sheet metal, is the need for an assembly of a completely different size and configuration for each particular clutch application. Each clutch application may require a different pulley diameter, number of peripheral belt receiving grooves, metal thickness, etc., as well as different thicknesses, diameters and configurations of clutch housings. This requires different manufacturing procedures and equipment to produce these various pulley and clutch housing assemblies, resulting in increased costs for the over-all clutch construction.
Still another problem that is encountered with prior pulley and clutch constructions is in the manufacturing procedures that are used in making the clutch housing and associated pulleys. In many of the stamped sheet metal type assemblies, the various components must be accurately sized and formed, especially certain openings, notches, etc., which are adapted to receive another component therein when forming the assembly. Any manufacturing procedure which requires extremely accurate sizing and dimensioning is usually more time consuming and expensive and requires more elaborate equipment than those procedures in which the tolerances are not as critical. This is especially true in stamping sheet metal components used in the clutch and pulley art in which a bearing is to be forced fitted into an opening formed in the pulley or housing to avoid the cost for welding, riveting, brazing or other means for securing the bearing in the opening.
Therefore, the need has existed for an improved clutch housing and pulley assembly and a method of making the same in which the assembly can be modified easily and inexpensively to meet the performance and operating requirements for various clutch applications, in which the assembly can be formed of sheet metal components, preferably from the same sheet metal stock, in which the assembly can be manufactured in an efficient and inexpensive manner, and in which a bearing can be installed easily and conveniently in a pulley or similar component.